In many downhole applications, stress concentrations or stress dipoles can develop due to zonal slip, reservoir compaction, placement of gravel pack packers, liner overlap, cement voids, and other environmental factors. The stress concentration can create ovalization and shear failures in tubular components, e.g. well casing, drill pipe, and production tubing used in the well environment. In some reservoirs and overburden rock, zonal slip and/or movements of the rock or formation can occur as a result of production processes or mild seismic events. The transverse shifting of subterranean material can induce the localized stress concentrations that lead to shear failure.
In other well-related environments, reservoir compaction can cause casing failures through tension, buckling, collapse, and shearing. The shearing failure mechanism can occur as localized deformation of casing over very small lengths. For example, wellbores drilled through layers of subsurface shale can be subjected to horizontal shifting of the subsurface shale when the corresponding reservoirs undergo a few feet of vertical compaction/subsidence. The casing shear failure usually is caused by displacement of the rock strata along bedding planes or along more steeply inclined fault planes. Casing deformation mechanisms include localized horizontal shear at weak lithology interfaces within the overburden, localized horizontal shear at the top of production and injection intervals, and casing buckling within the producing interval near, for example, perforations through the casing. These types of failures are expensive and can impede or even interrupt operation of the well.